Android Testing :: Custom View with Robolectric

build.gradle

dependencies {
    ...
    testCompile "org.robolectric:robolectric:3.1.1"
    ...
}

loading_view.xml

<?xml version="1.0" encoding="utf-8"?>
<com.workshop.customviewdemo.view.LoadingView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content">

    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/loading_view_spinner"
        android:visibility="visible"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:gravity="center"
        android:padding="10dip"
        >
        <ProgressBar
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Loading..."
            android:paddingLeft="10dip"
            />
    </LinearLayout>



    <TextView
        android:id="@+id/loading_text_view"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:visibility="invisible"
        />

</com.workshop.customviewdemo.view.LoadingView>

LoadingView.java

public class LoadingView extends RelativeLayout {
    public LoadingView(Context context) {
        super(context);
    }

    public LoadingView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public LoadingView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public void stopLoadingAndSetText(int resourceId) {
        TextView textView = (TextView) findViewById(R.id.loading_text_view);
        textView.setText(resourceId);
        textView.setVisibility(View.VISIBLE);

        findViewById(R.id.loading_view_spinner).setVisibility(View.GONE);
    }
}

LoadingViewTest.java

@RunWith(RobolectricTestRunner.class)
@Config(constants = BuildConfig.class, sdk = 21)
public class LoadingViewTest {

    private LoadingView loadingView;
    private View loadingSpinner;
    private TextView loadingTextView;

    @Before
    public void setUp() throws Exception {
        ActivityController<Activity> activityController = Robolectric.buildActivity(Activity.class);
        loadingView = (LoadingView) LayoutInflater.from(activityController.get()).inflate(R.layout.loading_view, null);
        loadingSpinner = loadingView.findViewById(R.id.loading_view_spinner);
        loadingTextView = (TextView) loadingView.findViewById(R.id.loading_text_view);
    }

}

LoadingViewTest02.java

@RunWith(RobolectricTestRunner.class)
@Config(constants = BuildConfig.class, sdk = 21)
public class LoadingViewTest {

    ...

    @Test
    public void testStopLoadingAndSetTextShouldHideTheSpinnerAndShowTheTextView() throws Exception {
        assertThat(loadingSpinner.getVisibility(), equalTo(View.VISIBLE));
        assertThat(loadingTextView.getVisibility(), equalTo(View.INVISIBLE));

        loadingView.stopLoadingAndSetText(R.string.unit_tests_ftw);

        assertThat(loadingSpinner.getVisibility(), equalTo(View.GONE));
        assertThat(loadingTextView.getVisibility(), equalTo(View.VISIBLE));
    }

}

LoadingViewTest03.java

@RunWith(RobolectricTestRunner.class)
@Config(constants = BuildConfig.class, sdk = 21)
public class LoadingViewTest {

    ...

    @Test
    public void testStopLoadingAndSEtTextShouldSetTheTextOnTheTextView() {
        loadingView.stopLoadingAndSetText(R.string.unit_tests_ftw);

        assertThat((String) loadingTextView.getText(), equalTo("Unit Tests FTW!!!"));
    }

}

Do you have an improved version with Kotlin & Mockk?

improved

Still in progress